title: Cerebral swelling after normothermic cardiopulmonary bypass.
abstract: BACKGROUND
  Marked cerebral swelling visible on magnetic resonance images has been found immediately after hypothermic (28 degrees C) cardiopulmonary bypass. The mechanism is unknown, but indices of cerebral ischemia are seen during rewarming from hypothermic bypass that are not present with normothermic bypass (37 degrees C).
  
  
  METHODS
  T1-weighted and fluid-attenuated inversion recovery magnetic resonance images were taken of seven patients undergoing routine coronary artery bypass surgery before, 1 h, and 7 days after the operation using normothermic bypass.
  
  
  RESULTS
  Marked cerebral swelling was seen in fluid-attenuated inversion recovery images in five of seven patients 1 h after bypass. Scans in four patients taken 7 days after bypass showed that the cerebral swelling had returned to normal. There was no change in cerebral ventricular size, and all patients had uncomplicated postoperative courses.
  
  
  CONCLUSIONS
  Normothermic bypass is followed by acute postoperative cerebral swelling. However, the amount of swelling was similar to that found in a previous study after hypothermic bypass. The mechanism of swelling is still obscure, and its relation to neurologic outcome is unknown.
authors.affiliation: Robert Steiner Magnetic Resonance Unit, Imperial College School of Medicine, London, United Kingdom. dharris@rpms.ac.uk
authors.forename: D N
authors.initials: DN
authors.lastname: Harris
authors.forename: A
authors.initials: A
authors.lastname: Oatridge
authors.forename: D
authors.initials: D
authors.lastname: Dob
authors.forename: P L
authors.initials: PL
authors.lastname: Smith
authors.forename: K M
authors.initials: KM
authors.lastname: Taylor
authors.forename: G M
authors.initials: GM
authors.lastname: Bydder
mesh_terms: D000368:Aged; D001929:Brain Edema / Q000175:diagnosis / Q000209:etiology*; D002315:Cardiopulmonary Bypass; D001026:Coronary Artery Bypass; D006801:Humans; D007036:Hypothermia, Induced; D008279:Magnetic Resonance Imaging; D008875:Middle Aged; D011183:Postoperative Complications